Обсуждение: pgsql: Doc: clarify that CREATE TABLE discards redundant unique constra

Поиск
Список
Период
Сортировка

pgsql: Doc: clarify that CREATE TABLE discards redundant unique constra

От
Tom Lane
Дата:
Doc: clarify that CREATE TABLE discards redundant unique constraints.

The SQL standard says that redundant unique constraints are disallowed,
but we long ago decided that throwing an error would be too
user-unfriendly, so we just drop redundant ones.  The docs weren't very
clear about that though, as this behavior was only explained for PRIMARY
KEY vs UNIQUE, not UNIQUE vs UNIQUE.

While here, I couldn't resist doing some copy-editing and markup-fixing
on the adjacent text about INCLUDE options.

Per bug #16767 from Matthias vd Meent.

Discussion: https://postgr.es/m/16767-1714a2056ca516d0@postgresql.org

Branch
------
REL_13_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/c6f8d17d04d1bf1ddcbe0f2293d8f1462a1379f4

Modified Files
--------------
doc/src/sgml/ref/create_table.sgml | 58 +++++++++++++++++++++++---------------
1 file changed, 36 insertions(+), 22 deletions(-)